Texture processing

Filament. Eully drawn flat yams and partially oriented (POY) continuous filament yams are available in yam sizes ranging from about 3.3—33.0 tex (30—300 den) with individual filament linear densities of about 0.055 to 0.55 tex per filament (0.5—5 dpf). The fully drawn hard yams are used directly in fabric manufacturing operations, whereas POY yams are primarily used as feedstock for draw texturing. In the draw texturing process, fibers are drawn and bulked by heat-setting twisted yam or by entangling filaments with an air jet. Both textured and hard yams are used in apparel, sleepwear, outerwear, sportswear, draperies and curtains, and automotive upholstery. 

There is a continuing interest to improve and extend the fimctional properties range of dairy proteins to provide both health benefits and their characteristic physical behaviors under different temperature, moisture, and pH conditions so that they may be included in foods that ordinarily do not contain them. One such research area is the extrusion texturization of whey proteins, which have resulted in dairy proteins with new characteristics imparted by a controlled texturization process, depending on the application desired (Hale et al., 2002 Manoi and Rizvi, 2008 Onwulata, 2009 Onwulata et al., 1998). Protein texturization is a two-step process that involves, first, the unfolding of the globular structure (denaturation) and, second, the alignments of the partially unfolded structures in the direction of mass flow in the extruder. The surface characteristics are imparted at the extruder die as the molten mass exits (Onwulata et al., 2003a). 

Cheftel, J. C., Kitagawa, M., and Queguiner, C. (1992). New protein texturization processes by extrusion cooking at high moisture levels. Food Rev. Int. 8, 235-275. 

Kinsella (16), in his recent review on texturized proteins, described the texturization process as follows the globular proteins (glycinins) in the aleurone granules become hydrated within the extruder barrel, are gradually unravelled, and are stretched by the shearing action of the rotating screw flites. 

Texturization Process at Various Temperatures. Changes in soy flour components during nonextrusion texturization at various temperatures were unlike those of extrusion texturization because shearing action does not occur in nonextrusion texturization. Therefore, a higher temperature (160 C) was required to produce a puffed product. Due to lack of shearing action, nonextrusion... 

Conventional, low-speed spun fibers must be further finished by drawing, although POY yarns are typically draw texturized. The drawing process adds strength by orientation of the molecular structures. Normal extensibility and proper tenacity are added by drawing the spun fibers to several times their as-spun length. The texturing process produces permanent crimp, loops, coils, or crinkles in the yarn that result in properties of stretch, bulk, absorbency, and improved hand (32). There are three basic types of... 

Murakami, M., Flux pinning of melt textured processed YBCO superconductors and their applications, in Studies of High Temperature Superconductors, Vol. 9 (A. V. Narlikar, ed.). Nova Science, New York, 1991, pp. 1. 

Considerable improvement in the production rates resulted from the introduction of frictional texturing [226], This process uses friction wheels. Essentially, one wheel revolution produces a fiber characterized by a twist number that parallels the ratio of the friction wheel diameter to the fiber diameter. Industrially practiced frictional texturing processes use a variety of wheels and are characterized by a delivery rate that approaches values in the range of 1000m/min . Gall presents a detailed account of this process [224]. 

The bicomponent fiber technology began in the 1960s on polyester and polyamide fibers. This technology encompasses a vast variety of polymers, filament shapes, and processes. As recent examples, Howe et al. [394], Wu [395], and Talley et al. [396] have disclosed spin-texture processes for the preparation of self-crimped polyamide bicomponent fibers. DuPont [397] disclosed the method for high-speed spinning bicomponent fibers. The use of a bicomponent yarn with another yarn to form a composite yarn bundle has been taught by Stevenson et al. [398] and others. 

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